FLORAL MECHANISMS 93 



Now the flower is ready to open and to receive 

 the call of a bee. For such a visit it has not long 

 to wait, for the bee has already come to the flowers 

 lower down on the spike, and gladly mounts to 

 this one, newly opened, with its fresh 

 store of nectar. He crawls deep into 

 the blossom; and in reaching down 

 for nectar he strikes his head against 

 the inner end of one of the crescents, 

 causing it to tilt and bob down its 

 anther bucket, thus spilling pollen 

 upon his back. 



But Nature sees to it that he does 

 not self-fertilise the flower. The pis- 

 til is still too short to reach his back, 

 so the bee, having finished with the 

 youngest flower of the spike, carries 

 his burden av^'ay to an older flower, /f^^ 



low down upon another spike: a ^^ 

 flower which has been open a day or development 

 more, and whose pistil has so elon- ^^ anthers 



OF SAGE 



gated and curved downward as to 



obstruct the entrance and surely to take up some 



pollen from the bee passing under. 



Thus is cross-fertilisation accomplished. It is 

 an important business, even though the trick con- 

 trivance of the pollen duster reminds us of the 



